Rain impact and rain erosion testing is important for evaluating aerospace components and materials. Many companies do not have internal test equipment to evaluate the resistance of their products to rain impact or erosion. Various products and materials can be submitted for testing by the University of Dayton Research Institute, located at Wright-Patterson Air Force Base. This facility uses a rotating arm device such as described in greater detail in William F. Adler, “Rain Impact Retrospective and Vision for the Future”; Wear 233-235, 1999, pp. 25-38. This test has become a standard in the industry for qualifying aerospace components and materials.
Rocket sleds are another device that has been used to evaluate water drop impacts. A rocket sled propels an array of test specimens through an extended sprinkler system, approximating on the ground what takes place in the atmosphere.
In addition, both ice and liquid water drop collisions have been evaluated in the GRCI Hydrometeor Impact Facility. A test specimen is mounted at the front end of a sabot which is propelled down the range by a small charge of gunpowder. The specimen impacts a single falling water drop.
W. F. Adler, J. W. Flavin, and J. P. Richards, “Multiple Simulated Waterdrop Impact Damage in Zinc Sulfide at Supersonic Velocities”, SPIE Vol. 1760, Window and Dome Technologies and Material III, 1992, pp. 303-315 describes that nylon bead impacts provide a good simulation of water drop impact damage on zinc sulfide for a wide range of impact conditions.